Wee'uns will need a dry warm place, they can't take too much being cold when they're small. Depending on your ground and climate, they may need more than an ark to keep them warm and dry over winter.
If your stable isn't too far from your fields, and you can put up some sort of shelter in the field, you could do what I do with my overwinter weaners. They're indoors at night and when the ground is very wet and cold, or is frozen or under snow, and daytimes when the weather and ground are suitable they are outside - in my case, in the so-called orchard with a wind- and rain-proof, well-strawed shelter in a corner.
They need stimulation, do pigs. If they're in a stable 24x7 they will get bored. You will either need to entertain them, and/or keep coming up with new toys and diversions to keep them amused, or will have to put up with a lot of screaming and some fighting, or will overfeed them so that they sleep most of the time - and cost you more and have waaayyy too much backfat when they come to be butched.
So if you can provide some outside space they can run about in when the conditions are suitable, you will have happier, fitter pigs, all of you will have a lot more fun, and they'll cost less to rear and taste better to boot!
In terms of getting them from stable to field and back again - it's very very simple. As soon as they are used to you and the bucket meaning dinner, they'll follow that bucket to Timbuktoo if you lead them slowly

After a few days of "breakfast in the field, supper in the stable", you'll find they run ahead of you to where the food is. Clever things, pigs, and very very greedy
